Gas turbine system of the continuous combustion type



Oct. 4, 1938. A. LYSHOLM GAS TURBINE SYSTEM OF THE CONTINUOUS COMBUSTION TYPE Filed Jan. 19, 1955 A. I 3 u m 9 1v Patented Oct. 4, 1938 PATENT OFFICE GAS TURBINE SYSTEM OF THE CONTINUOUS COMBUSTION TYPE All Lysholm,

Aktiebolaget poration of Sweden Application January 19, 1935, Serial No.

Stockholm, Sweden, Milo, Stockholm,

assignor to Sweden, a cor- In Germany January 20, 1934 Claims.

The present invention relates to gas turbine systems of the continuous combustion type as distinguished from the intermittent combustion or explosion type and has particular reference to systems of this character in which motive fluid is produced by internal combustion of fuel with a gaseous combustion supporting medium compressed in one or more compressors which are in turn driven by one or more turbines utilizing the 10 products of such combustion as motive fiuid.

The general object of the invention is to provide a system of the above character including axial flow gas turbines and double rotation radial flow gas turbines, and to arrange the said turbine types with respect to the compressors, driven engines and the flow of fuel and combustion supporting medium in such a manner that the different parts of the gas turbne system may be operated under their most advantageous conditions. no The invention is applicable to many different specific arrangements of gas turbine systems, and for purposes of illustration I have shown in the accompanying drawing two embodiments of apparatus for carrying the invention into effect. In the systems illustrated the combustion supporting medium employed is air, in which liquid fuel such as fuel oil is burned to produce motive fluid. For convenience I will refer, but without limitation, to the combustion supporting medium no as air, it being understood that other media having equivalent functions maybe employed instead. Also the fuel may be a gaseous medium such as blast furnace gas, suitably compressed.

In the drawing forming a part of this specification:

Fig. 1 is a more or less diagrammatic illustration of a gas turbine system embodying the invention,

Fig. 1a is a portion of the apparatus shown in 40 Fig. 1, drawn to a larger scale, and

Fig. 2 is a view similar to Fig. 1 and showing a different embodiment of the invention.

Referring to Fig. 1, the system shown in this figure, comprises a double rotation radial flow 45 turbine indicated at H], which turbine is preferably of the Ljungstrom type with reaction blad- I ing and full admission of motive fluid to the blade system. The gas turbine system further comprises an axial flow turbine 12 which is pref- 50 erably provided with a reaction blade system and which may be of the type described in my copending application Serial No. 710,465 filed February 9, 1934 (matured into Patent No. 2,080,425, granted May 18, 1937).

55 The turbine I0 comprises two oppositely rotating shafts l4 and 16 having the usual turbine rotors associated therewith, and on the extensions of the turbine shafts are mounted respectively the rotors laand 20 of the two sections 22 and 24 of arotary or centrifugal compressor indicated generally at 26. Other forms of compressor may be employed. The sections of the compressor are serially connected by means, of a suitable connection 28. The shaft of the axial flow turbine I2 is independent of the turbine shafts l4 and I6 and drives by means of a suitable toothed gearing 10 v 32 the shaft 34 of a propeller 36 constituting the driven part of the gas turbine plant. Air is drawn into the low pressure compressor section 22 through the inlet 38 and. is discharged through 15 conduit 28 to the high pressure compressor section 24. The finally compressed air is delivered from the outlet 40 of the compressor to a conduit 42 which leads to the inlet of a combustion chamber generally indicated at 44. Fuel is admitted to chamber 44 through pipe 46 under the control of suitable valve means indicated at 48. The amount of fuel admitted to the combustion chamber may be regulated in any suitablemanner to obtain the desired temperature of the motive fluid 25 discharged through conduit 52 to turbine the present instance, the valve 48 is controlled by temperature responsive means consisting of a 56 connecting the bellows with the valve member 58 of valve 48. As illustrated in the drawing valve 48 is arranged to throttle the amount of fuel delivered to the combustion chamber upon rise of the temperature of the motive fluid passing through conduit 52 and admitted to turbine 10 and to increase the supply of fuel upon drop Due to this control the temperature of the motive fluid passing through conduit 52 may be kept constant at any desired value.

As will be seen from the drawing, the combustion chamber 44 is divided into two compartments 60 and 62, the inner compartment 60 serving as combustion chamber proper, whereas the outer compartment 62 together with the annular space between the conduit 52 and the conduit 64 forms a passage through which compressed air may be conducted to the turbine 19 without having been 5 heated in the combustion chamber 60. Thus, the motive fluid supplied to the turbine is divided into two separate streams, one'of which is at high temperature and the other of which is at a relatively lower temperature, the latter stream being employed to protect certain of the turbine parts against the temperature of the high temperature stream of motive fluid. The two streams of motive fluid are maintained in separated state to a point adjacent to the inlet of the turbine blading and are then mixed and delivered to the blade system of the turbine for expansion therein. The exhiisist motive fluid is passed through the outlet The axial flow turbine I2 receives motive fluidi from chamber through conduit 68 which is surrounded by a conduit 10 connected to conduit 42 by means of a by-pass pipe 12 provided with a suitable valve means 14. Air is conducted through pipe I2 into the space formed between the conduits 68 and I0, and the motive fluid for turbine I2 is thus divided into two streams of different temperatures in the same manner and for the same purpose as described with regard to the motive fluid admitting means for turbine I0. Through apertures I6 in the conduit 68 part of the air admitted by means of. pipe 12 enters the inner conduit 68, thereby cooling the motive fluid in the said conduit so thatthe axial flow turbine I2 will receive the motive fluid at a lower temperature than the double rotation radial flow turbine I0. After having been expanded the motive fluid is exhausted through the outlet I8. In order to keep the temperature of the motive fluid admitted to turbine I2 at any desired constant value, the amount of air passed through pipe I2 is regulated by temperature responsive means consisting of a thermostat 80 located in conduit 68, a bellows 82 and a rod 84 connecting the bellows with the valve member 86 of valve 14. Upon rise of the thermostat temperature valve I4 will increase the cross-section of passage, and consequently a greater amount of air will pass through pipe 12 and enter the conduit 68, thereby reducing the thermostat temperature to the desired normal value. Should, on the other hand, the thermostat temperature fall below the normal value, the valve 14 will be caused to close the passage of air to such an extent that the desired temperature of the mixture in the conduit 68 will be restored.

As is known to those skilled in the art, double rotation radial flow turbines may be driven with motive fluid of very high temperatures at very high efflcienoies due to the fact that the diameters of the first stages, where the temperature is highest, are very small and that the deformations due to the creeping effect are practically of. no consequence in turbines of this type. On the other hand, double rotation radial flow turbines cannot be built for considerably great quantities of motive fluid and they further require complicated and expensive gearing mechanism if the speed is to be reduced, as, for instance, is the case in marine engines. As will be seen from the drawing, the compressor turbine is of the double rotation radial flow type, while the useful power turbine is of the axial flow type and receives its motive fluid at a lower temperature than the compressor turbine. A gas turbine power plant having a motive fluid inlet temperature of about 1070 F. can be constructed to operate with a thermal efficiency of above 30 per cent. However, axial flow turbines cannot-be driven at so high a temperature. The same thermal efficiency may be attained, however, if the axial flow turbine is driven with motive fluid of only 870 F., and the temperature of the motive fluid for the double rotation radial flow turbine is increased to 1200 F. The turbine power plants illustrated in the drawing are arranged and designed under observance of the above mentioned considerations, it being understood that the temperatures are named by way of example only. The compressor turbine thus operates under the most ad- 5 vantageous conditions securing a high thermodynamic efliciency, while the gearing provided between. the useful power turbine and the driven part becomes very simple. The fact that the two compressor sections are drivn by the double rotation turbine makes it possible to operate the compressor sections with different speeds relatively to each other as the existing working conditions may require.

While in the embodiment illustrated in Fig. 1 a 15 reduction of the temperature of the motive fluid admitted to the axial flow turbine is accomplished by mixing the motive fluid with compressed air of a relatively low temperature, Fig. 2 shows an embodiment in which this purpose is achieved by the provision of two combustion chambers in the manner to be described in the following. The general arrangement is the same in this figure as in Fig. l,- and like parts are designated with the same reference numerals.

In the system shown in Fig. 2 the compressed air delivered by the compressor 26 is led through conduit 88 into a flrstcombustion chamber 90 into which fuel is admitted through pipe 46 under the control of valve means 92. Valve 92 is controlled by means of a thermostat 94 located in conduit 98 through which motive fluid is admitted to the axial flow turbine I2. The thermostat acts upon a bellows" members 96 operative upon change of thermostat temperature to admit more fuel to the combustion chamber if the temperature in conduit 98 tends to fall and to throttle the fuel supply upon rise ofv temperature. Part of the combustion gases containing air in excess passes through conduit I00 into a second combustion chamber I02 where further heating by combustion is effected by means of fuel admitted through pipe I04 and controlled by valve I06 in response to variations of temperature of the motive fluid passing through conduit I08 to the turbine I0. Regulation of valve I06 is effected by means of thermostat IIO located in pipe I08,

bellows H2 and connecting rod H4 in the same manner as described with reference to the regulation of valve 92, that is, the temperature of the motive fluid as admitted to the turbines is automatically maintained at a constant or substantially constant value.

From the foregoing description it will be understood that due to the additional heating of the motive fluid in the second combustion chamber I02 the temperature of the motor fluid as supplied to the double rotation radial flow turbine will be higher than that of the motive fluid admitted to the axial flow turbine. In accordance with the previously mentioned example the motive fluid may be heated in the first combustion chamber 90 to a temperature of about 870 F. and in the second combustion chamber I02 to a temperature of about 1200 F.

Other controlling means than those described above may be employed. While for the sake of simplicity relatively simple systems have been illustrated, it is to be understood that the invention is not restricted in its scope to systems 70 of the specific kinds hereinbefore described as illustrative embodiments, but is to be understood as including all such variations in apparatus and, in mode of operation as may fall within the scope of the appended claims when they are construed 75 constituent of motive fluid to be expanded in said turbines, means providing a combustion chamber, means for conducting the compressed gaseous medium from said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, means for conducting motive fluid from said combustion chamber to each of said turbines, and means including regulating mechanisms operable independently of each other and each operating under the influence of the motive fluid supplied to a different one of said turbines for separately producing from the gaseous medium compressed by said compressor means a first motive fluid supply for expansion in said radial flow turbine and a second motive fluid supply of lower temperature than said first motive fluid supply for expansion in said axial flow turbine.

2. A gas turbine system of the continuous combustion type including a double rotation radial flow turbine, an axial'flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing a gaseous constituent of motive fluid to be expanded in said turbines, means providing a combustion chamber, means for conducting the compressed gaseous medium from said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, means arranged to conduct motive fluid from said combustion chamber to each of said turbines for expansion therein from substantially the same initial pressure, and means including regulating mechanisms operable independently of each other and each operating under the influence of the motive fluid supplied to a difierent one of said turbines for separately producing from the gaseous medium compressed by said compressor means a first motive fluid supply for expansion in said radial flow turbine and a second motive fluid supply of lower temperature than said first motive fluid supply for expansion in said axial flow turbine.

3. A gas turbine system of the continuous com-' bustion type including a double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing a gaseous constituent of motive fluid to be expanded in said turbines, means providing a combustion chamber, means for conducting the compressed gaseous medium from said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, means arranged to conduct motive fluid from said combustion chamber to each of said turbines for expansion therein from substantially the same initial pressure, said turbines being arranged to expand motive fluid through substantially the same pressure range from substantially the same initial pressure to substantially the same exhaust pressure, and means including regulating mechanisms operable independently of each other and each operating under the influence of the motive fluid supplied to a diiferent one of said turbines for separately producing from the gaseous bedium compressed by said compressor means a first motive fluid supply for expansion in said radial flow turbine and a second motive fluid supply of lower temperature than said first motive fluid supply for expansion in said axial flow turbine.

4. A gas turbine system of the continuous combustion type including a double rotation radial flow turbine arranged to exhaust against substantially atmospheric back pressure, an axial flow turbine independent of said radial flow turbine with respect to speed of operation and arranged to exhaust against substantially atmospheric back pressure, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing a gaseous constituent of motive fluid to be expanded in said turbines, means providing a combustion chamber, means for conducting the compressed gaseous mediumfrom said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, means arranged to conduct motive fluid from said combustion chamber to each of said turbines for ex pansion therein from substantially the same initial pressure, and means including regulating mechanisms operable independently of each other and each operating under the influence of the motive fluid supplied to a different one of said turbines for separately producing from the gaseous medium compressed by said compressor means a first motive fluid supply for expansion in said radial flow turbine and a second motive fluid supply of lower temperature than said first motive fluid supply for expansion in said axial flow turbine.

5. A gas turbine system of the continuous combustion type including a double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing a gaseous constituent of motive fluid to be expanded in said turbines, means providing a combustion chamber, means for conducting the compressed gaseous medium from said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, means for conducting motive fluid from said combustion chamber to each of said turbines, said turbines and the last mentioned means being arranged to provide'for flow of motive fluid to said turbines and expansion of the motive fluid therein in parallel, and means including regulating mechanisms operable independently of each other and each operating under the influence of the motive fluid supplied to a different one of said turbines for separately pro ducing from the gaseous medium compressed by said compressor means a first motive fluid sup- 6 A gas turbine system of the continuous com- 7 bustion type including a. double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven bysaid axial flow turbine, compressor means driven by said radial flow turbine for compressing air, means providing a combustion chamber, means for conducting the compressed air from said compressor means to said combustion chamber, means for supplying fuel to the combustion chamber, means for conducting motive fluid from the combustion chamber to said radial flow turbine, means for conducting motive fluid from the combustion chamber to said axial flow turbine, and regulating means for supplying a governed quantity of compressed air to the motive fluid delivered from the combustion chamber to said axial flow turbine.

7. A gas turbine system of the continuous type including a double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing air, means providing a combustion chamber, means for conducting the compressed air from said compressor means to said combustion chamber, means for supplying fuel to the combustion chamber, means for conducting motive fluidv from, the combustion chamber to said radial flow turbine, means for regulating the fuel supply in response to variations in the temperature of the motive fluid as supplied to said radial flow turbine, means for conducting motive fluid from the combustion chamber to said axial flow turbine, means for supplying compressed air to the motive fluid delivered from the combustion chamber to said axial flow turbine, and means for regulating the compressed air supply in response to variations in the temperature of the motive fluid as supplied to said axial flow turbine.

8. A gas turbine system of the continuous combustion type including a double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing air, means providing a combustion chamber, means for conducting the compressed air from said compressor means to said combustion chamber, means for supplying fuel to the combustion chamber, a conduit for conducting motive fluid from said combustion chamber to said radial flow turbine, a second conduit for conducting motive fluid from said combustion chamber to said axial flow turbine, regulating means responsive to the temperature of motive fluid in the first-mentioned conduit for regulating the supply of fuel to the combustion chamber, a by-pass conduit for bypassing air from said compressor means to the second-mentioned conduit, and regulating means responsive to the temperature of motive fluid in the second-mentioned conduit for controlling the flow of air through said by-pass conduit.

9. A gas turbine system of the continuous combustion type including a double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing air, means providing a first combustion chamber, a conduit for conducting air from said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, a conduit for conducting motive fluid from said combustion chamber to said axial flow turbine, means for regulating the fuel supply to said combustion chamber in response to variations in the temperature of the motive fluid as supplied to said axial flow turbine, conduit means including a second combustion chamber for conducting motive fluid from said first combustion chamber to said radial flow turbine, means for supplying fuel to said second combustion chamber to increase the temperature of the motive fluid supplied to said radial flow turbine as compared with the temperature of the motive fluid delivered by said first combustion chamber, and means for regulating the fuel supply to said second combustion chamber in response to variations in the.

temperature of the motive fluid as supplied to said radial flow turbine, the last mentioned means being adjusted to maintain the temperature of the motive fluid delivered to the radial flow turbine at a higher value than the temperature of the motive fluid supplied to the axial flow turbine.

10. A gas turbine system of the continuous combustion type including a double rotation radial flow turbine, an axial flow turbine independent of said radial flow turbine with respect to speed of operation, power output means driven by said axial flow turbine, compressor means driven by said radial flow turbine for compressing a111, means providing a first combustion chamber, a conduit for conducting air from said compressor means to said combustion chamber, means for supplying fuel to said combustion chamber, means arranged to conduct motive fluid from said combustion chamber to each of said turbines for expansion therein from substantially the same initial pressure, the last mentioned means including a second combustion chamber arranged in the path of flow of motive fluid between said flrst combustion chamber and said radial flow turbine for increasing the temperature of the motive fluid delivered from said first combustion chamber, a first regulating mechanism operating under the influence of the motive fluid as supplied to said axial turbine for regulating the fuel supplied to said flrst combustion chamber, means for supplying fuel to said second combustion chamber, and a second regulating mechanism operating under the influence of the motive fluid as supplied to said radial flow turbine for regulating the fuel supply to said second combustion chamber, said second regulating mechanism being adjusted to maintain the temperature of the motive fluid delivered to the radial flow turbine at a higher value than the temperature of the motive fluid supplied to the axial flow turbine.

ALF LYSHOLM. 

